| abstract |
A polyolefin microporous membrane has excellent self-discharge characteristics when the polyolefin microporous membrane is incorporated as a separator in a battery. The polyolefin microporous membrane has a membrane thickness change rate of 0% or more and 15% or less with respect to 100% of the membrane thickness of said polyolefin microporous membrane that has not heated nor compressed, wherein said membrane thickness change rate is obtained when said polyolefin microporous membrane is compressed under heat at a temperature of 80° C. at a pressure of 1 MPa for 60 minutes. |